Process of producing dyeings on cotton.



1 ERNST WUGK, F HfiCHST-ON-THE-MAIN, GERMANY, ASSIG-NOR TO FARBWERKE VORM.-

UNITED STATES PATENT oFFIcE-j.

mEIsrEn; Looms & nnumne, or HiiGI-IST-ON-THE-MAIN, GERMANY.

To all whome't may concern: Be it known that I, ERNST WUGK, Ph; D., chemist, a citizen of the Empire of Ger-.

many, residing at Hochst-on-the-Ma'in, Gerlowing is a specification.

In'U. S. Patent No. 1,012,619 is descrlbed a process of producing dyeings on'cotton,

capable of being discharged, b using monoazodyestufis obtained by com inin a'diazotized aminonaphtholsulfonic acid with meta-phenylenediamin or aderiuative thereof. In elaborating this invention, I havefound that by replacing in the said mo-noa'zp dyestufis the metadiamin by an aromatlc dioxycompound capable of being coupled twice, there are also obtained dyestuffs which produce. on the fiber very intense violet to brown tints, fast to'washing, 'by.

treatment with nitrodiazo benzene, and

which can be discharged to a ure white. The constitutionof these dyestu s probably corresponds'to formula; I

of sulfo groups.

Example I: The cotton fabric 1s padded I with a 1% solution of the dyestufi produced by combining diazotized v2. 5.' 7 jam1non'aphtholsulfonic acid with resorcin, 'an'd subsequently treated in the'usual manner with 'p-nitrodiazobenzene. Thus an intense beautiful violet-brown tint, of excellent fastness to soap and capable of being readily discharged, is obtained.

Example II: The cotton fabricis padded Specification of Letters Patent.

rnocnss or rnonucme DYEING'S' on corron.

Patented Mar. 18,1913.-

'A'pplication filed February .7, 1912.. Serial No. 676,036.

by combining diazotiz'ed 2.5.7- aminonaphtholsulfonic acid with 2.7 dioxynaphthalene,

and subsequently treated in the usual manner with p-n trodi zobenzene. Thus a reddlsh-brown tint, 0' excellent fastness to soap and capable of being readily discharged, is

'naphtholsulfonic acid with l.8-dioxynaph- --thalene 3.6-disulif0nic acid, and subsequently treatedin the usualimanner with p-nitro diazobenzene. Thus a violet tint,'of excel lent fastnes's to soap and. capable of being readily'discharged, is obtained.

Having now described my invention, I declare that what I claim is: j

1. The herein-described process of producing dyeings on cotton, fast to washing and capable of being discharged, by applying on the fabric a dyestuff obtained by combining adiazotized aminonaphtholsulfonic 'acid with anfaromatic dioxy compound ca pable of being coupled twice, and then treatmg the dyestuffs on the fiber with nitrodiazobenzene.

2. The herein-described process of producing dyeings on cotton, fastto washing and capable of being dischar ed, by applying on the fabrica dyestu obtained by combining diazot-ized 2.5.7 aminonaphth'olwith a 1% solution of the dyestufi"- produced sulfonic acid with 1.8-dioxynaphthalene- 3.6-disulfonic acid, and then treating the dyestuif on the fiber with nitrodiazobenzene. In testimony whereof,I afiix my signature in presence of two'witnesses. Z ERNST W IIGK.' Witnesses:

JEAN GRU'ND,

CARL GRUND. 

